From a4fe17653f9668fdc53ccc6044e77205eb6279bf Mon Sep 17 00:00:00 2001
From: Arjen Hiemstra <ahiemstra@heimr.nl>
Date: Mon, 11 Jul 2022 14:03:53 +0200
Subject: [PATCH] Remove alignment requirements from data in vertex/index
 buffers

We now rely on auto-vectorisation to generate the appropriate SSE or
other instruction set code. We can also assume that takes care of
handling any alignment requirements and thus remove the need for manual
alignment things.
---
 src/libkwineffects/kwinglutils.cpp | 15 ++++-----------
 1 file changed, 4 insertions(+), 11 deletions(-)

diff --git a/src/libkwineffects/kwinglutils.cpp b/src/libkwineffects/kwinglutils.cpp
index e4cfb5ddb2..230c39887a 100644
--- a/src/libkwineffects/kwinglutils.cpp
+++ b/src/libkwineffects/kwinglutils.cpp
@@ -1335,11 +1335,6 @@ static const uint16_t indices[] = {
     2029, 2028, 2031, 2031, 2030, 2029, 2033, 2032, 2035, 2035, 2034, 2033, 2037, 2036, 2039, 2039, 2038, 2037,
     2041, 2040, 2043, 2043, 2042, 2041, 2045, 2044, 2047, 2047, 2046, 2045};
 
-template<typename T>
-T align(T value, int bytes)
-{
-    return (value + bytes - 1) & ~T(bytes - 1);
-}
 
 class IndexBuffer
 {
@@ -1380,7 +1375,6 @@ void IndexBuffer::accommodate(int count)
         return;
     }
 
-    count = align(count, 128);
     size_t size = 6 * sizeof(uint16_t) * count;
 
     // Create a new buffer object
@@ -1743,7 +1737,7 @@ void GLVertexBufferPrivate::reallocatePersistentBuffer(size_t size)
 
     // Round the size up to 64 kb
     size_t minSize = qMax<size_t>(frameSizes.average() * 3, 128 * 1024);
-    bufferSize = align(qMax(size, minSize), 64 * 1024);
+    bufferSize = qMax(size, minSize);
 
     const GLbitfield storage = GL_DYNAMIC_STORAGE_BIT;
     const GLbitfield access = GL_MAP_WRITE_BIT | GL_MAP_PERSISTENT_BIT | GL_MAP_COHERENT_BIT;
@@ -1825,7 +1819,7 @@ void GLVertexBufferPrivate::reallocateBuffer(size_t size)
 {
     // Round the size up to 4 Kb for streaming/dynamic buffers.
     const size_t minSize = 32768; // Minimum size for streaming buffers
-    const size_t alloc = usage != GL_STATIC_DRAW ? align(qMax(size, minSize), 4096) : size;
+    const size_t alloc = usage != GL_STATIC_DRAW ? qMax(size, minSize) : size;
 
     glBufferData(GL_ARRAY_BUFFER, alloc, nullptr, usage);
 
@@ -1920,7 +1914,7 @@ void GLVertexBuffer::unmap()
 {
     if (d->persistent) {
         d->baseAddress = d->nextOffset;
-        d->nextOffset += align(d->mappedSize, 16); // Align to 16 bytes for SSE
+        d->nextOffset += d->mappedSize;
         d->mappedSize = 0;
         return;
     }
@@ -1931,7 +1925,6 @@ void GLVertexBuffer::unmap()
         glUnmapBuffer(GL_ARRAY_BUFFER);
 
         d->baseAddress = d->nextOffset;
-        d->nextOffset += align(d->mappedSize, 16); // Align to 16 bytes for SSE
     } else {
         // Upload the data from local memory to the buffer object
         if (preferBufferSubData) {
@@ -1943,7 +1936,7 @@ void GLVertexBuffer::unmap()
             glBufferSubData(GL_ARRAY_BUFFER, d->nextOffset, d->mappedSize, d->dataStore.constData());
 
             d->baseAddress = d->nextOffset;
-            d->nextOffset += align(d->mappedSize, 16); // Align to 16 bytes for SSE
+            d->nextOffset += d->mappedSize;
         } else {
             glBufferData(GL_ARRAY_BUFFER, d->mappedSize, d->dataStore.data(), d->usage);
             d->baseAddress = 0;